A variety of single cellular and multicellular pathogens including bacteria, fungi, mites (e.g., Demodex folliculorum) and lice (e.g., Pediculus humanus capitis) can infect the eyelashes, the eyelid margin and the base of the eyelash follicles. The initial symptoms of eyelid margin infections can be mild, so that patients may not seek treatment until the infection has advanced to include symptoms such as burning, flaking, crusting, tearing, irritation, itching, redness in eyelid margins, a gritty, foreign body sensation and light sensitivity. Left untreated, eyelid margin infections can have serious consequences, including permanent scarring of the lid margins, loss of the eyelashes, and misdirected eyelashes, which in turn, can result in various sight-threatening corneal lesions. For example, misdirected eyelashes can induce trauma to the corneal epithelium leading to corneal ulceration and pannus formation, i.e., abnormal blood vessel or fibrous tissue growth in the cornea. Moreover, parasitic infections due to mites (e.g., Demodex folliculorum) and lice (e.g., Pediculus humanus capitis) are often overlooked in differential diagnosis of corneal disease, resulting in further delays in treatment.
Present methods of treatment of eyelash and eyelid margin infections generally involve daily eyelid scrubbing with mild shampoo, or other cleansing formulas, application of warm compresses, and administration of topical or systemic antibiotics, or topical steroids. The efficacy any one of these methods varies depending on the particular pathogen. Eyelid scrubbing and antibiotics are typically ineffective against eukaryotic pathogens such as Demodex, lice or yeast. Remedies such as eyelid scrubbing require long-term patient compliance. Topical ointments may cause visual blurring, which may be difficult for some patients to tolerate. There is a continuing need for effective, broad spectrum and easy to use treatments for eyelash and eyelid margin infections.